Head mounted image displays (e.g. helmets, goggles, and eyeglasses incorporating miniature displays) and other compact display systems which provide data in alphanumeric, video, or graphic form have applications in avionics, medicine, entertainment, and wearable computers, as well as numerous other fields. There are three principal types of prior art head mounted display systems: “see-through systems,” in which the displayed electronic image is combined with the ambient imagery so that the user can see both images; “see-around systems” in which the displayed image occludes a part of the ambient imagery; and “full-immersion systems” in which the entire ambient image is blocked, so that the user sees only the electronically generated image. All three types of systems use various means, including lenses and the like, to project the image into the viewer's eyes.
The simplest systems are of the see-around type in which the electronic display is provided with one or more lenses and suspended in front of the user's eyes. A principal limitation of the device is that the display and optical system must be moved with respect to the head, or the head must be moved, to enable the user to see ambient imagery in the occluded field. A significant part of the occlusion results from the supporting structure and housing, as well as from the display itself. A second limitation of such devices is that the device is suspended from the head (or helmet, strap or other support borne by the head), so that the mass of apparatus adds an undesirable weight and/or torque to the head. A third limitation of the device is that position of the exit pupil of the optical system cannot be fixed accurately, meaning that the exit pupil of the optical system must be large enough to accommodate various motions of the device that occur during use.
Full-immersion systems have many of the same limitations as see-around systems. The head mounted system must be removed to view any ambient imagery. Typically, the systems comprise displays and lens systems similar to the see-around display, or comprise a display, lens system and reflective screen. These systems involve high weight, torque and volume. Full-immersion systems often cannot be safely used in many public environments.
See-through systems involve the most complex optical designs. Generally, the see-through system comprises a display, lens system, and viewing screen or combiner. All of the limitations of the see-around display are shared by the see-through display, except for the need to remove the head-mounted system to see ambient images. However, for this benefit, it is necessary to add further optical components, thus increasing the weight, complexity and cost of the system. See-through systems often offer a lower quality viewing experience for users wanting to focus the majority of their attention on the content displayed.
All three of the above head mounted display types have the further limitation of requiring that the optical systems be mounted in goggles, helmets, strap-on bands, unusually bulky wearable device enclosures having large visors and the like, rather than more conventional optical supports. This limitation requires users to become accustomed to wearing such devices, as well as making the user very conspicuous when wearing such a device.
Conventional binocular image display devices use a large cross sectional area or flexible joints of the head mounting devise to limit moment loading on the binocular optics and distortion of the alignment of the optics and micro displays that can result from user forces. The bulk and  unusual shapes often do not appeal to users.
Thus, there is a need for a device that overcomes the above and other disadvantages.